In his email, seen by Third Sector, Knox described the decision to contact the media as "an extraordinary act of self-harm that endangers the service".

He added: "The service is more important than any one individual and this is why I feel that I need to step down, not least to demonstrate this."

Various staff and volunteers, who wished to remain anonymous, had contacted Third Sector with concerns about the management of the organisation since it was formed by the merger two years ago of Warwick District Citizens Advice Bureau and Stratford-upon-Avon and District Citizens Advice Bureau.

Most complaints were about the treatment of staff and volunteers. One said they had never felt so ignored and disrespected, and said staff shortages were putting employees under severe pressure.

Another said there was widespread discontent and low morale because the views of staff and volunteers were being ignored. "The irony is that we champion employment rights, but they are badly observed here," the source said.

Some were particularly upset about the dismissal in July last year of the volunteer John Boden, who had volunteered for 10 years.

Former colleagues of Boden were considering taking industrial action to support his claim for reinstatement, but are now re-evaluating their plans after news of Knox's departure.

The charity, which has offices in Leamington Spa and Stratford, had an income of £665,000 in the year ending 31 March 2017.

Yvonne Hunter, chair of the charity, emailed colleagues saying she was "saddened and disheartened to find that someone has approached a national charity magazine to try to highlight their discontent with the running of our Citizens Advice".

Hunter's email, seen by Third Sector, added: "I know that many people feel that the organisation has lost some of its human touch and we need to address that, but also recognise that with a new organisation there would be difficult times in bringing people along together."

She said that the charity's HR committee would meet on Friday 16 March. An action plan would then be drawn up to address issues already raised by staff and volunteers.

She added: "People who are managing this organisation are working incredibly hard to ensure that our organisation is a success."

In a statement sent to Third Sector, Hunter said Knox had been pivotal in successfully managing the merger of the two bureaux and she would be sad to see him go.

"I would like to take this opportunity to give our thanks for the enormous contribution he has made to the charity," she said.

She said two reviews of the decision to ask Boden to step down found that the conclusion was reasonable, although the process could have been better.

"The CASW trustee board is reviewing internal procedures to ensure that all best practice is followed," she said. "We are committed to improving our communications across the organisation.

"We are a local charity supported by over 150 volunteers. Together with our 29 paid staff we serve a population of over 250,000 and meet the need of over 9,000 clients per year. We will continue to deliver an excellent service to the people of South Warwickshire."

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